读写web.config的简单问题?

yumanqing 2008-08-08 10:50:53

在程序中有一段代码是这样的:
创建数据库->将新数据库的连接字符串写入web.config->读取连接字符串->向新数据库插入一行数据

现在代码都写好了，现在的问题是写入web.config也已经写入了,可是读取
string keyNameLocal = "strConFor" + CoNo.ToString() + "Local";
connectionString = System.Configuration.ConfigurationManager.AppSettings[keyNameLocal];
的时候总是提示是null,停止调试，打开web.config查看，的确是写入了,我感觉好像当时写在内存中，读取的好像不是最新的数据
可是 webc.config已经保存了呀；郁闷...

关键代码如下:



using System;

using System.Collections.Generic;

using System.Text;

using System.Xml;

using System.Web;

using System.Reflection;



public enum ConfigFileType

{

    WebConfig,

    AppConfig

}



namespace SalesServer.Operate

{

    /// <summary>

    ///  web.config操作类

    /// </summary>

    public class ReadWriteConfig

    {

        public string docName = String.Empty;

        private XmlNode node = null;

        private int _configType;

        public string message;



        public int ConfigType

        {

            get { return _configType; }

            set { _configType = value; }

        }



        #region 读取

        public string GetValue(string key)

        {     //读取

            try

            {

                XmlDocument cfgDoc = new XmlDocument();

                loadConfigDoc(cfgDoc);

                // retrieve the appSettings node  

                node = cfgDoc.SelectSingleNode("//appSettings");

                if (node == null)

                {

                    throw new InvalidOperationException("appSettings section not found");

                }

                // XPath select setting "add" element that contains this key to remove      

                XmlElement addElem = (XmlElement)node.SelectSingleNode("//add[@key='" + key + "']");

                if (addElem == null)

                {

                    message = "此key不存在！";

                    return message;

                }

                message = System.Configuration.ConfigurationManager.AppSettings[key];

                return message;

            }

            catch

            {

                message = "操作异常，获取value值失败！";

                return message;

            }

        }

        #endregion



        #region 增加

        public string SetValue(string key, string value)

        {   

            XmlDocument cfgDoc = new XmlDocument();

            loadConfigDoc(cfgDoc);

            // retrieve the appSettings node   

            node = cfgDoc.SelectSingleNode("//appSettings");

            if (node == null)

            {

                throw new InvalidOperationException("appSettings section not found");

            }

            try

            {

                // XPath select setting "add" element that contains this key       

                XmlElement addElem = (XmlElement)node.SelectSingleNode("//add[@key='" + key + "']");

                if (addElem != null)

                {

                    message = "此key已经存在！";

                    return message;

                }

                // not found, so we need to add the element, key and value   

                else

                {

                    XmlElement entry = cfgDoc.CreateElement("add");

                    entry.SetAttribute("key", key);

                    entry.SetAttribute("value", value);

                    node.AppendChild(entry);

                }

                //save it   

                saveConfigDoc(cfgDoc, docName);

                message = "添加成功！";

                return message;

            }

            catch

            {

                message = "操作异常，添加失败！";

                return message;

            }

        }



        #endregion



        #region 保存web.config

        private void saveConfigDoc(XmlDocument cfgDoc, string cfgDocPath)

        {

            try

            {

                XmlTextWriter writer = new XmlTextWriter(cfgDocPath, null);

                writer.Formatting = Formatting.Indented;

                cfgDoc.WriteTo(writer);

                writer.Flush();

                writer.Close();

                return;

            }

            catch

            {

                throw;

            }

        }



        #endregion



        #region 删除

        public string removeElement(string elementKey)

        { // 删除

            try

            {

                XmlDocument cfgDoc = new XmlDocument();

                loadConfigDoc(cfgDoc);

                // retrieve the appSettings node  

                node = cfgDoc.SelectSingleNode("//appSettings");

                if (node == null)

                {



                    throw new InvalidOperationException("appSettings section not found");

                }



                XmlElement addElem = (XmlElement)node.SelectSingleNode("//add[@key='" + elementKey + "']");

                if (addElem == null)

                {

                    message = "此key不存在！";

                    return message;

                }

                // XPath select setting "add" element that contains this key to remove      

                node.RemoveChild(node.SelectSingleNode("//add[@key='" + elementKey + "']"));

                saveConfigDoc(cfgDoc, docName);

                message = "删除成功！";

                return message;

            }

            catch

            {

                message = "操作异常，删除失败！";

                return message;

            }

        }

        #endregion



        #region 修改

        public string modifyElement(string elementKey, string elementValue)

        { //修改

            try

            {

                XmlDocument cfgDoc = new XmlDocument();

                loadConfigDoc(cfgDoc);

                // retrieve the appSettings node  

                node = cfgDoc.SelectSingleNode("//appSettings");

                if (node == null)

                {

                    throw new InvalidOperationException("appSettings section not found");

                }

                // XPath select setting "add" element that contains this key to remove      

                XmlElement addElem = (XmlElement)node.SelectSingleNode("//add[@key='" + elementKey + "']");

                if (addElem == null)

                {

                    message = "此key不存在！";

                    return message;

                }



                addElem.SetAttribute("value", elementValue);

                //save it   

                saveConfigDoc(cfgDoc, docName);

                message = "修改成功！";

                return message;

            }

            catch

            {

                message = "操作异常，修改失败！";

                return message;

            }

        }

        #endregion



        #region 加载

        private XmlDocument loadConfigDoc(XmlDocument cfgDoc)

        {

            // load the config file   

            if (Convert.ToInt32(ConfigType) == Convert.ToInt32(ConfigFileType.AppConfig))

            {

                docName = ((Assembly.GetEntryAssembly()).GetName()).Name;

                docName += ".exe.config";

            }

            else

            {

                docName = HttpContext.Current.Server.MapPath("web.config");

            }

            cfgDoc.Load(docName);

            return cfgDoc;

        }

        #endregion



    }

}

//写入

ReadWriteConfig config = new ReadWriteConfig();

config.ConfigType = (int)ConfigFileType.WebConfig;

config.SetValue("strConFor" + CoNo.ToString() + "Local", "Persist Security Info=false;InitialCatalog=Sales";User Id=sa;Password=;server=127.0.0.1");

//读取

string keyNameLocal=("strConFor" + CoNo.ToString() + "Local",;

 System.Configuration.ConfigurationManager.AppSettings[keyNameLocal];

...全文

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yumanqing 2008-08-08

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谢谢，先在想想吧其它办法，等待...

linekery 2008-08-08

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[Quote=引用 13 楼 andy_1027 的回复:]
配置文件必须是程序重启后才会加载，你如果急着读出来还是不要用WEB。CONFIG，用其它配置文件好了。
[/Quote]

不用重启

自动重新加载

只要让程序空闲出来 - - 问题是一个事件都没执行完程序当然不重新加载啊
你等事件完了之后在读取得了呗。。。

andy_1027 2008-08-08

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配置文件必须是程序重启后才会加载，你如果急着读出来还是不要用WEB。CONFIG，用其它配置文件好了。

zzlazio 2008-08-08

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晕，上面代码顺手写的，忘记返回了connectionString 了

zzlazio 2008-08-08

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写和读在同一事件里的话，个人认为在读的时候，重新先读一边配置文件比较合适



    private void ReadConfig()

    {

        Configuration config = WebConfigurationManager.OpenWebConfiguration(Request.ApplicationPath);

        AppSettingsSection sc = (AppSettingsSection)config.GetSection("appSettings");

        string connectionString = sc.Settings[appKeys[keyNameLocal]].Value

    }

windboyzsj 2008-08-08

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System.Configuration.Configuration config = System.Configuration.ConfigurationManager.OpenExeConfiguration(HttpContext.Current.Server.MapPath("web.config"));

config.AppSettings.Settings.Add("strConFor", "Persist Security Info=false;InitialCatalog=Sales;User Id=sa;Password=;server=127.0.0.1");

config.Save(ConfigurationSaveMode.Modified);

//读取

string keyNameLocal = "strConFor";

System.Configuration.ConfigurationManager.RefreshSection("appSettings");

string conn = System.Configuration.ConfigurationManager.AppSettings[keyNameLocal];

或者你换个方法，来添加。

yumanqing 2008-08-08

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[Quote=引用 5 楼 windboyzsj 的回复:]
再次搜索之前重载一下

...
System.Configuration.ConfigurationManager.RefreshSection("appSettings");
string conn = System.Configuration.ConfigurationManager.AppSettings[keyNameLocal];
...
[/Quote]

也不行，继续等待中，不解决晚上奥运会看的就不安心呀，帮忙一下。。。。。

格拉 2008-08-08

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mark

linekery 2008-08-08

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[Quote=引用 5 楼 windboyzsj 的回复:]
再次搜索之前重载一下

...
System.Configuration.ConfigurationManager.RefreshSection("appSettings");
string conn = System.Configuration.ConfigurationManager.AppSettings[keyNameLocal];
...
[/Quote]

主动重载不会结束当前会话么？那样所有权限之类的就都没了

linekery 2008-08-08

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修改了重新加载得你当前干的事情干完了才行呀 - - 程序才会主动重新加载
如果有验证的话会自动回默认页的 - - 在一个事件里也不能强迫立刻重新加载的
你应该创建数据库作为单独事件执行完毕之后会自动加载的以后就能查到了

windboyzsj 2008-08-08

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再次搜索之前重载一下

...
System.Configuration.ConfigurationManager.RefreshSection("appSettings");
string conn = System.Configuration.ConfigurationManager.AppSettings[keyNameLocal];
...

yumanqing 2008-08-08